Recent Investigations on the Cultivation of Rubber 1

Abstract

EXPERIMENTS on the cultivation and preparation of rubber are being pushed forward at several stations, and the results are discussed in the agricultural journals circulating in tropical and subtropical countries. Methods of tapping the tree have been studied in Hawaii, and found to have a marked effect on the yield of latex. Trees tapped with a V-cut gave much less than others with a vertical cut, the greater yield, however, being partly due to the fact that the length of the incision in the latter case is greater than in the former. No advantage was gained from the use of four cuts daily instead of two. The effects of nitrate of soda on the flow of latex have also been studied. Fertilisers are in use in rubber plantations for increasing the growth and vigour of the trees, and it now appears that nitrate of soda also increases the flow of latex. In one experiment a group of five trees yielded 0.9 oz. of dry rubber in three days before applying the nitrate, and 1.3 oz. in the three days following its application, each tree receiving half a pound of the fertiliser. How far the method is economical has yet to be determined. All these experiments were made with Ceara rubber trees.